Hypothesis for the histogenesis of atypical epithelial proliferation in the stomach

Atypical epithelial proliferation has been described in various ways, such as ATP, and IIa-subtype, an adenoma, and as dysplasia in the stomach. Although the gross findings are variable, showing a protruded and/or concave appearance, these lesions have an intimate relationship with the intestinal metaplasia. Atypical epithelial proliferation lesions develop in 2 fashions. The first type, of proliferation is a superficial type with the capability of transition to the deep non-atypical glands, and may arise in association with a superficial type of intestinal metaplasia. The second type of proliferation may arise from an area affected by complete intestinal metaplasia, in the mitotic region in the bottom of the gland. The majority of the protruded types may arise from the first lesion described, and the majority of the concave types from the second.